Engineering Commons^™

Modeling And Performance Evaluation Of Machining Spindle With Active Magnetic Bearings, Jerzy T. Sawicki, Eric H. Maslen, Kenneth R. Bischof

Mechanical Engineering Faculty Publications

Active magnetic bearings (AMBs) are increasingly employed in the machine tool industry to exploit their advantages over classical bearings such as high speed capability, rotation accuracy, high stiffness, and accurate displacement tracking capability. Furthermore, the possibility of on-line monitoring of the machining process (e.g., cutting force measurement, tool wear) makes AMB spindles very appealing to the High-Speed Machining (HSM) industry. Despite significant progress already reached in HSM technology, there remain numerous open challenges in modeling and control of magnetic bearings as applied to machining spindles. These include optimum control given AMB magnetic saturation levels, management of nonlinear effects, reduction of …

Integrating Globalization Processes Into The Rational Unified Process, Omar Bahy Badreddin

Archived Theses and Dissertations

No abstract provided.

North American Standard For Cold-Formed Steel Framing -- Header Design, 2007 Edition (Reaffirmed 2012), American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

Understanding Coulomb Effects In Nanoscale Schottky-Barrier-Fets, Klaus M. Indlekofer, Joachim Knoch, Joerg Appenzeller

Other Nanotechnology Publications

We employ a novel multiconfigurational self-consistent Green's function approach (MCSCG) for the simulation of nanoscale Schottky-barrier-field-effect transistors (SB-FETs). This approach allows the calculation of electronic transport with a seamless transition from the single-electron regime to room-temperature FET operation. The particular improvement of the MCSCG stems from a self-consistent division of the channel system into a small subsystem of resonantly trapped states for which a many-body Fock space approach becomes numerically feasible and the rest of the system which can be treated adequately on a conventional mean-field level. The Fock space description allows for the calculation of few-electron Coulomb charging effects …

Physics Of Ultrathin-Body Silicon-On-Insulator Schottky-Barrier Field-Effect Transistors, Joachim Knoch, M Zhang, Joerg Appenzeller, S Mantl

Other Nanotechnology Publications

In this article we give an overview over the physical mechanisms involved in the electronic transport in ultrathin-body SOI Schottky-barrier MOSFETs. A strong impact of the SOI and gate oxide thickness on the transistor characteristics is found and explained using experimental as well as simulated data. We elaborate on the influence of scattering in the channel and show that for a significant barrier the on-state current is insensitive to scattering once the mean free path for scattering is larger than a characteristic length scale. In addition, recent efforts to lower the Schottky barrier at the source/drain channel interfaces are presented. …

Evaluation Of Current Stormwater Design Criteria Within The State Of Florida (2007), Stormwater Academy

BMP Trains Research and Publications

No abstract provided.

Acuta Enews June 2007, Vol. 36, No. 6

ACUTA Newsletters

ln This lssue

From the President Carmine Piscopo, RCDD, ACUTA President

Board Report .............. Riny Ledgerwood, San Diego State Univ., ACUTA Sec./Treasurer

Tech Talk: Waiting for TechTalk 2.0, the New, lmproved Version................. Kevin Tanzillo, Dux PR

DC Update ... Jeanne Jansenius, Sewanee, The University of the South

Another Hit to the Cabling Budget: Electrician Shortage = Higher Cabling Costs............. Gary Audin

FYI: Useful lnformation from the Campus.................. Student Monitor

Web Tip: What's New at acuta.org?............. Aaron Fuehrer, ACUTA lnformation Technology Manager

Sign Up Today for Preconference Seminars

lnfo Links....................... Randy Hayes, Univ. of Northern lowa

ACUTA Web Seminar: lP Video …

Reduced Shell Model Calculations Of 111Sb And 112Sb, E. Dikmen, T. Akyürek

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

The low-lying states of the mid-heavy odd-even 111Sb and odd-odd 112Sb isotopes are calculated for the first time within the shell model framework. The shell model calculations have been carried out within the reduced model space including the single particle orbits 1d5/2, 0g7/2, 1d3/2, 2s1/2. We obtain the energy spectra for the 111Sb and 112Sb isotopes in the reduced model space by using CD-Bonn two-body effective nucleon-nucleon interaction. The energy spectra are compared to the experimental results to give some discussion about the low-lying states of 111Sb and 112Sb. © 2007 Chinese Physical Society and IOP Publishing Ltd.

Prevention Of Voc Releases From Bridge Painting Operations, Theodore Hopwood Ii, Rick Younce, Sudhir Palle

Kentucky Transportation Center Research Report

Bridge maintenance painting employs solvent-based coatings that generate volatile organic compounds (VOCs) that contribute to air-quality problems. Methods for capturing VOCs during normal Kentucky Transportation Cabinet (KYTC) maintenance painting operations were investigated. One method, activated carbon adsorption, is adaptable to KYTC operations. Related factors including area of bridge, coating systems, containment volumes and VOC out gassing rates were reviewed. A commercial source of activated carbon adsorption equipment was identified and issues related to employing that technology for bridge painting were identified.

Singular Perturbation Theory For Dc-Dc Converters And Application To Pfc Converters, Jonathan W. Kimball, Philip T. Krein

Electrical and Computer Engineering Faculty Research & Creative Works

Many control schemes for dc-dc converters begin with the assertion that inductor currents are "fast" states and capacitor voltages are "slow" states. This assertion must be true for power factor correction (PFC) converters to allow independent control of current and voltage. In the present work, singular perturbation theory is applied to boost converters to provide rigorous justification of the time scale separation. Krylov-Bogoliubov-Mitropolsky (KBM) averaging is used to include switching ripple effects. A relationship between inductance, capacitance, load resistance, and loss resistances derives from an analysis of an approximate model. Similar results hold for buck and buck-boost converters. An experimental …

Control Methods In Dc-Dc Power Conversion -- A Comparative Study, Kai-Tak Wan, Jingsheng Liao, Mehdi Ferdowsi

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Several control techniques for dc-dc power conversion and regulation have been studied in this paper. Analog approaches have briefly been described since the focus is the newly developed digital techniques. Principles of operation, advantages, and disadvantages of each control method have been described. Simulation results have been used to compare the performance and accuracy of digital control techniques.

Measuring Gas-Liquid Distribution In A Pilot Scale Monolith Reactor Via An Industrial Tomography Scanner (Its), M. (Muthanna) H. Al-Dahhan, A. Kemoun, A. R. Cartolano, S. Roy, R. Dobson, J. Williams

Chemical and Biochemical Engineering Faculty Research & Creative Works

An Industrial Tomography Scanner (ITS) Was Designed and Developed to Study and Quantify the Phase Distribution in a Two-Phase Flow Pilot Scale Monolith Reactor that Was 24 In. (0.60 M) in Diameter and 192 In. (4.9 M) in Height. the Monolith Reactor Was Operated Co-Current Up-Flow in the Taylor Flow Regime with Water as the Liquid Phase and Air as the Gas Phase. the Cross-Sectional Holdup Distributions Were Measured at Three Axial Elevations. the Operating Conditions Were Selected to Bracket Commercial Operating Conditions for Fixed Bed Monolithic Reactor Systems. the Results Show that its Can Capture the Flow Features in …

Strengthening Of A Reinforced Concrete Bridge With Externally Bonded Steel Reinforced Polymer (Srp), Alexis Lopez, Nestore Galati, Tarek Alkhrdaji, Antonio Nanni

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper introduces steel reinforced polymer (SRP) as a way to strengthen civil structures. This technique consists of cords formed by interwoven high-strength steel wires embedded within a polymeric resin. a comprehensive study addressing analysis, design, installation, load rating and monitoring of a bridge strengthened with this technology is reported. the SRP system was easily installed, demonstrating its similarity to more traditional fiber reinforced polymer (FRP) strengthening techniques. Load tests were performed to evaluate the bridge structural behavior prior and after the strengthening in accordance with AASHTO specifications, showing that the rehabilitation performed as predicted and therefore created the possibility …

Explosive-Driven Mini-System Based On Shock Wave Ferromagnetic Seed Source And Loop Magnetic Flux Compression Generator, Sergey I. Shkuratov, Evgueni F. Talantsev, Jason Baird, Allen H. Stults, Larry L. Altgilbers

Mining Engineering Faculty Research & Creative Works

Completely explosive pulsed power mini-systems based on the transverse shock wave ferromagnetic generator (FMG) served as a seed source and loop magnetic flux compression generator (LFCG) as a pulsed power amplifier were proposed, designed, built and tested. The physical principles and design of the developed FMG-LFCG system are described in detail. Experimental data are presented for the explosive operation and electrical performance of the system.

Differential Evolution Approach For Reactive Power Optimization Of Nigerian Grid System, G. A. Bakare, G. Krost, Ganesh K. Venayagamoorthy, U. O. Aliyu

Electrical and Computer Engineering Faculty Research & Creative Works

The goal of reactive power dispatch is to minimize the system losses and improve the system voltage profiles at all times. This is achieved by adjusting various generating units' excitation systems continuously, discrete tap positions of on-load tap changers of transformers as well as switching of correct doses of inductors or capacitors. This is a mixed integer non-linear optimization problem. In this paper, the differential evolution (DE), a novel evolutionary computation technique which was originally designed for continuous problems is applied to solve this problem. DE appears to ally qualities of established computational intelligence (CI) techniques with a more striking …

Analysis Of Beam Propagation In 90-Degree Holographic Recording And Readout Using Transfer Functions And Numerical 2-D-Laplace Inversion, Monish Ranjan Chatterjee, Partha P. Banerjee, George Nehmetallah

Electrical and Computer Engineering Faculty Publications

Recently, 2-D-Laplace analysis of recording and readout of edge-holograms was reported. Numerical Laplace inversion was examined for simple test cases. Inversion algorithms are applied to examine beam shaping and distortion in photovoltaic and photorefractive materials.

Recycling Practices For Environmental Materials, Sudhir Palle, Steve Higgins, Theodore Hopwood Ii

Kentucky Transportation Center Research Report

Two environmental materials, tree and brush debris and large animal roadkill carcasses were investigated. The disposal methods for these materials were reviewed as opportunities/methods for possible recycling. KYTC established several pilot composting operations in 2006. These were monitored during their preliminary stages of operation.

Analysis Of Army Transformation And The Effects On Customer Ordering Behavior, Joseph M. Colacicco

Theses and Dissertations

The United States Army began a major force transformation in 2003, which required a significant shift in logistics support constructs. This thesis provides an in-process review of the effects of the current transformation efforts on supply effectiveness and attempts to determine factors that influence customer ordering behavior. Specifically, the thesis sought to answer three subproblems addressing the effect of transformation on supply effectiveness, the correlation of supply effectiveness metrics to customer ordering behavior, and other potential sources of variance in ordering behavior. The subproblems were answered through an examination of the supply document histories of two Brigades, one legacy Brigade …

Optimizing Distribution Sensor Placement For Border Patrol Interdiction Using Microsoft Excel, Adrian C. Patrascu

Theses and Dissertations

The purpose of this research was to develop an electronic sensor placement model for border security. A model was developed using Microsoft Excel, with some add-on capabilities, to optimize the placement of electronic sensors on a border network given a pre-determined budgetary constraint. The model is capable of handling multiple sensor types, which are placed together as packages, and allows for daytime, nighttime, or 24 hour operation of each sensor type. Additionally, each sensor can be assigned a specific range and detection probability curve within the given range. The model is capable of optimizing either average coverage, or minimum coverage, …

A Small-Scale 3d Imaging Platform For Algorithm Performance Evaluation, Steven A. James

Theses and Dissertations

In recent years, world events have expedited the need for the design and application of rapidly deployable airborne surveillance systems in urban environments. Fast and effective use of the surveillance images requires accurate modeling of the terrain being surveyed. The process of accurately modeling buildings, landmarks, or other items of interest on the surface of the earth, within a short lead time, has proven to be a challenging task. One approach of high importance for countering this challenge and accurately reconstructing 3D objects is through the employment of airborne 3D image acquisition platforms. While developments in this arena have significantly …

Controller Design For Accurate Antenna Pointing Onboard A Spacecraft, Victor M. Barba

Theses and Dissertations

Controller design for a spacecraft mounted flexible antenna is considered. The antenna plant model has a certain degree of uncertainty. Additionally, disturbances from the host spacecraft are transmitted to the antenna and need to be attenuated. The design concept explored herein entails feedforward control to slew the antenna. Feedback control is then used to compensate for plant uncertainty and to reject the disturbance signals. A tight control loop is designed to meet performance specifications while minimizing the control gains. Simulations are conducted to show that the integration of feedforward control action and feedback compensation produces better responses than the implementation …

Performance Analysis And Comparison Of Multiple Routing Protocols In A Large-Area, High Speed Mobile Node Ad Hoc Network, Daniel K. Roberts

Theses and Dissertations

The U.S. Air Force is interested in developing a standard ad hoc framework using "heavy" aircraft to route data across large regions. The Zone Routing Protocol (ZRP) has the potential to provide seamless large-scale routing for DOD under the Joint Tactical Radio System program. The goal of this study is to determine if there is a difference between routing protocol performance when operating in a large-area MANET with high-speed mobile nodes. This study analyzes MANET performance when using reactive, proactive, and hybrid routing protocols, specifically AODV, DYMO, Fisheye, and ZRP. This analysis compares the performance of the four routing protocols …

Hyperspectral Imagery Target Detection Using Improved Anomaly Detection And Signature Matching Methods, Timothy E. Smetek

Theses and Dissertations

This research extends the field of hyperspectral target detection by developing autonomous anomaly detection and signature matching methodologies that reduce false alarms relative to existing benchmark detectors, and are practical for use in an operational environment. The proposed anomaly detection methodology adapts multivariate outlier detection algorithms for use with hyperspectral datasets containing tens of thousands of non-homogeneous, high-dimensional spectral signatures. In so doing, the limitations of existing, non-robust, anomaly detectors are identified, an autonomous clustering methodology is developed to divide an image into homogeneous background materials, and competing multivariate outlier detection methods are evaluated for their ability to uncover hyperspectral …

Structural Stability Of A Joined-Wing Sensorcraft, Brandon J. Adams

Theses and Dissertations

This thesis employed a multi-disciplinary design approach to determine the structural stability of the Boeing Joined-Wing SensorCraft. Specifically, this thesis sought to characterize the free vibration modes, ensure a buckling safe design and determine the influence of the geometric and aeroelastic nonlinearities associated with this joined-wing design. The clamped free vibration modes were developed for a wind tunnel model and were compared to the free-free vibration modes, several differences were found. Linear static analyses were performed on numerous maneuver loads and gust conditions to determine the critical loading condition. The SensorCraft was then redesigned for the critical load case to …

Development Of Cursor-On-Target Control For Semi-Autonomous Unmanned Aircraft Systems, Joshua D. Crouse

Theses and Dissertations

The research presented in this thesis focuses on developing, demonstrating, and evaluating the concept of a Cursor-on-Target control system for semi-autonomous unmanned aircraft systems. The Department of Defense has mapped out a strategy in which unmanned aircraft systems will increasingly replace piloted aircraft. During most phases of flight autonomous unmanned aircraft control reduces operator workload, however, real-time information exchange often requires an operator to relay decision changes to the unmanned aircraft. The goal of this research is to develop a preliminary Cursor-on-Target control system to enable the operator to guide the unmanned aircraft with minimal workload during high task phases …

Automated Carrier Landing Of An Unmanned Combat Aerial Vehicle Using Dynamic Inversion, Nicholas A. Denison

Theses and Dissertations

Dynamic Inversion (DI) is a powerful nonlinear control technique which has been applied to several modern flight control systems. This research utilized concepts of DI in order to develop a controller to land an Unmanned Combat Aerial Vehicle (UCAV) on an aircraft carrier. The Joint Unmanned Combat Air System (J-UCAS) Equivalent Model was used as the test aircraft. An inner-loop DI controller was developed to control the pitch, roll, and yaw rate dynamics of the aircraft, while an outer-loop DI controller was developed to provide flight path commands to the inner-loop. The controller design and simulation were conducted in the …

Effect Of Prior Aging On Fatigue Behavior Of Im7/Bmi 5250-4 Composite At 191°C, Christine G. Ladrido

Theses and Dissertations

IM7/BMI 5250-4 with carbon fiber orientations [± 45] and [0/90] were aged in air at 191 °C for up to 1000 hours. The weight loss was analyzed during the aging process. Tension to failure tests were performed on both the unaged and aged specimens to establish a baseline for the Ultimate Tensile Strengths and Young's Modulus. Tension-tension cyclic load fatigue testing was conducted on the specimen to determine the effect of prior aging on the fatigue response of the composite. Cyclic strain accumulation was not influenced by prior aging, but it was influenced by the stress levels applied. [± 45] …

The Aerodynamic Performance Of The Houck Configuration Flow Guides, Dermot N. Killian Ii

Theses and Dissertations

In an effort to explore efficient wing designs for UAV's, the Air Force is investigating the patented Houck Aircraft Configuration, which is a joined-wing aircraft with curved flow guides of varying camber connecting the upper and lower wingtips. Models were drawn in three-dimensions using Solidworks® with upper and lower wings drawn as identical NACA 2412 airfoil sections for all models. A variety of airfoil sections between the upper and lower wingtips were drawn and rotated to achieve a combination of cant and angle of attack variation. Subsequently, a solid part was lofted through these sections and merged with the upper …

Damage Considerations Of A Flexible Micro Air Vehicle Wing Using 3-D Laser Vibrometry, Leo L. Mendoza Jr.

Theses and Dissertations

In recent years there has been a major push towards a new class of unmanned aerial vehicles: micro air vehicles. A great amount of research has been done towards the aerodynamics, aeroelasticity, construction, and flight characteristics of flexible wing micro air vehicles. However, there has not been much research done regarding possible structural deficiencies of a flexible micro air vehicle wing. The focus of this research is to evaluate the effects of damage on a flexible micro air vehicle wing, particularly its natural frequencies and mode shapes, using three dimensional laser vibrometry. The flexible micro air vehicle wing studied was …

The Effects Of Environment On The Interlaminar Shear Performance Of An Oxide/Oxide Ceramic Matrix Composite At Elevated Temperature, Patrick D. Laffey

Theses and Dissertations

This research investigated the interlaminar shear performance of an oxide/oxide ceramic matrix composite consisting of Nextel™ 720 fibers in a high purity, porous alumina (Al₂O₃) matrix. The interlaminar shear performance was observed in both tension and compression of double notched specimens (DNS) at 1200 °C. Interlaminar shear creep behavior was examined in both laboratory air and in steam environment at 1200 °C. In air, the creep stress was -6.5 MPa. In steam creep stresses included -4.0, -5.0, and -6.5 MPa. Primary and secondary creep regimes were observed in all air creep tests and the creep test …